1. Basic definition of color tolerance
Simply put, the color tolerance is the deviation error between the LED color coordinate measured by the instrument and the color coordinate of the standard light source (unit: SDCM)
Do you know the color tolerance and color rendering index of lamp beads?
Under the standard light source, each color temperature value will have a unique corresponding coordinate value in the CIE coordinates, but our LED light source may actually have the same color temperature value corresponding to multiple different CIE coordinates in the test. At this time, color tolerance is required. The value is used as a limiting criterion.
(The color tolerance of LEDs for general lighting is limited to less than 5 SDCM)
McAdam Oval 2700K
As shown in the right picture, point A is the standard light source 2728K
X: 0.463 /Y: 0.42 Color temperature: 2728K
Point B is the instrument test coordinate
X: 0.4602 Y: 0.415 Color temperature: 2728K
It can be seen that the color temperature of point B is the same as that of A standard light source, but the CIE coordinates are different, and the color will also have errors.
2. The basic concept of color rendering index
Color rendering index (Ra): The similarity index of the lighting source and natural sunlight, the higher the closer (the highest is 100)
There are 15 CIE RI standard color samples, R1-R8 are typical color rendering indexes
R9-R15 is a special color rendering index
Ra represents the average color rendering index, generally only R1-R8 are calculated
That is, Ra=(R1 R2 R3 R4 R5 R6 R7 R8)/8
CRI graphic detailed explanation
General color rendering index
Do you know the color tolerance and color rendering index of lamp beads? Do you know the color tolerance and color rendering index of lamp beads?
Special color rendering index
Do you know the color tolerance and color rendering index of lamp beads? Do you know the color tolerance and color rendering index of lamp beads? In traditional LED light sources, the blue chip yellow phosphor used is lacking from the R9 color sample (saturated red), so the R9 value directly affects the overall color rendering index; usually without the red spectral radiant power supplement, the R9 value is generally negative If the radiant power of the red spectrum increases, the value of R9 will increase, which will directly lead to an increase in the overall color rendering index. For example, our company’s current RA>80 products all add red powder operation, so R9 will be >0
